# Copyright 2023 The Flax Authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

"""Functionality for inspecting jax tracers."""

import jax

from .. import errors


def current_trace():
  """Returns the innermost Jax tracer."""
  return jax.core.find_top_trace(())


def trace_level(main):
  """Returns the level of the trace of -infinity if it is None."""
  if main:
    return main.level
  return float('-inf')


def check_trace_level(base_level):
  level = trace_level(current_trace())
  if level != base_level:
    raise errors.JaxTransformError()
